Process for making furfural resins



' Patented Apr. 10, 1928.

UNITED STATES PATENT" OFFICE.

JOHN P. TRICKEY, OI EVANS TON, AND CARL B. MINER, OF CHICAGO, ILLINOIS, AS- SIGNOBS TO THE QUAKEB OATS COMPANY, OF CHICAGO, ILLINOIS, A CORPORA- TION OF NEW JERSEY.

PROCESS FOR MAKING FUIRFURAL BESINS.

in Drawing. Application med May 26, 1924, Serial No. 715,815. Renewed February '27, 1928.

This invention pertains to methods or processes. for making resinous materials from furane derivatives and more particularly to processes for making furfural resins.-

It is the purpose of this invention to provide a rapid, inexpensive and eflicient process for making resinous materials from furane'derivatives. More specifically, one of the objects of this invention is to provide an eflicient catalyst for causing rapid resinification of furane derivatives and particularly furfural.v

A further object of this invention is to provide a non-corrosive catalyst for this purpose so that after the resin has been formed any slight quantities of. the catalyst which may remain in the resin will impart no undesirable properties thereto, Furthermore, it is an object of this invention toprovide a catalyst, all or a part of which if desired may be allowed to remain in the resinous material without imparting any qualities thereto which would render the resin undesirable for most uses.

Under properly controlled conditions certain reactions will take place'in furane de-.

rivatives, such as furfural, resulting in the formation of resinous materials. We have discovered that such reactions maybe made totake place by at least three different methods. First, furfural by itself may becontinuously heated for a long period of time and after several months the reaction will be manifested by the formation of small amounts of soft resinous material. Second, furfural may be allowed to stand without heating for a year or more in the presence of a suitable catalyst and the reaction will also manifest itself by a slight resinification. Third, a furane derivative, such as furfural, may be heated in the presence of a catalyst and resinification will take place much more quickly than with the independent use of either heat or a catalyst.

\Ve have discovered that under properly controlled conditions various salts act as very eflicient catalysts for use in the resinificat-ion of furane derivatives, such as furfural. Among the catalysts we have found effective are aluminum chloride, ferric chloride, lead acetate and iron pyromucate. Under most con t s m n m chler d that many other metallic salts will act in a similar manner and, therefore, the term metallic salt that serves as a catal st for the reaction refers to those metalllc salts only which act in the nature of catalytic agents in producing a furfural resin from furfural.

These salts may be preferably addedin a dry condition to the furfural in quantities amounting to substantially 1% of the weight of the furfural, The furfural is then heated while being constantly agitated. If furfural is treated in this manner, using aluminum chloride as a catalyst the resinification will become manifest bythe formation of a jelly-like substance after several hours heating at a temperature approximating 100 C. However, in order to securea more rapid rate of reaction for commercial purposes, the use of higher temperatures above atmospheric pressure is desirable. In fact, the rate at which the reaction takes place may be readily controlled either by the form of catalyst or combination of catalysts used or by regulation of the temperature.

As the reaction proceeds a soft viscous resin first forms which later changes to a semi-solid stage. The resin in this form is fusible and is soluble in acetone and the like but is insoluble in water. If the reaction is allowed to proceed to a conclusion, the fusible, soluble product is transformed into an infusible, insoluble solid.

used, as catalysts are not removed from the i roduct, their presence in the dry state and in the small quantities mentioned will impart no undesirable qualities to the resin for most uses. The use of these comparatively inactive materials, especially in a dry state,

accordingly ofiers many advantages over the use of solutions of active reagents. Strong I y active reagents, if not entirely removed m the'product, would of course corrode the moulds used in shaping objects made of the product and also seriously impair the electrical insulation properties'and stability of the roduct.

, By t us properly controlling the speed and extent of the reaction as above described, we are able to securea product of various degrees of consistency depending upon the stage at which the reaction is] stopped. Furthermore, the resulting product formed from stopping the reaction at an particular intermediate stage maybe su stantially permanentl retained. at its existing consistencyv by t e removal'of the catalyst.

Since the 'reaction'is readily controlled in accordance with our inventionand may be arrested at any stage in the resinification of the furane derivative, the resulting resins made without departing from the scope and principle of the invention set forth or innucleus or other ring 11110181 tended to be set forth in the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States, is:

1. The process of making a furfural resin which comprises heatin furfural in the resence of a metallic sa t which is present in a quantity onlyto serve as a catalyst for the reaction. I

2. The process of obtaining a resinous substance which comprises treating furfural with' a metallic salt t at serves as a catalyst for the reaction.

3. The process of obtaining a. resinous reaction product which comprises subjecting 'furfura' -to the action of a metallic salt which is resent in a quantity only to serve as a cata yst for the reaction, and to such temperature as to produce a fusible soluble resin.

4. The resin whi comprises submitting furfural witha metallic salt that serves as a catalyst for the reaction to such temperature and pressure as to produce a fusible soluble resin. 5. The rocess .of obtaining a furfural resin whic com rises heating furfural under pressure wit 'a metallic salt serving as process of obtaining a furfural a catalyst for the reaction to a temperature 4 above the atmospheric boiling point of furfural until a fusible soluble resin is formed. 6; The rocess of obtaining a furfural resin whic com rises heating furfural with a catalyst embo ying at least one metallic salt that serves as a catalyst for the reaction to such a temperature and under such pressure that a non-gelatinous resinous reaction product is produced.

In witness whereof, we have hereunto subscribed our names.

- CARL S. MINER. j

JOHN P. TRICKEY. 

